Trapped in the Ocean

The Pod inside the Bus

"These pods are built to be compatible with all S.H.I.E.L.D. aircraft, submarines, spacecraft. On impact, the atmospheric adaptation must have tried to compensate. We slowly sank as it increased the density of the outer walls."

After the Bus was captured and being used by the Centipede Project, Coulson's Team members Leo Fitz and Jemma Simmons tracked it down during a mission while trailing Project Centipede members, but were captured by Grant Ward. After being brought aboard the Bus, they both managed to scramble away from their captors and locked themselves inside the Medical Pod to save themselves from Ward, who had been given orders to kill them. Ward however simply ejected the pod from the plane while flying over open ocean.[3]

Fitz and Simmons survived the fall into the ocean, however, because the pod was designed to be compatible with a variety of S.H.I.E.L.D. vehicles, ranging from aircraft to submarines.

The Pod being ejected from the Bus.

The pod slowly sank 90 feet to the seafloor below. Trapped inside of the pod at the bottom of the ocean, Fitz rigged a makeshift distress beacon, but knowing that there was probably no one listening, he and Simmons began to resign to their fate. Eventually, Simmons realized how they could use the medical supplies scattered around the pod to escape back to the surface. After setting up their escape plan, they found there were only enough resources for one of them to escape safely; Fitz willingly sacrificed his safety so that Simmons could reach the surface safely while he nearly drowned.[4]